Conventional microprocessors and digital signal processors require the use of specialized instructions and hardware to execute loops and nested loops in program execution. For example, specialized instructions may require additional fields to specify the number of iterations to execute a loop. Further, specialized registers are required to specify the start address and end address of each loop. In VLIW (very large instruction width) processors, special execution units need to be provided to indicate the number of loop iterations or the location of the pointer to an address location that stores the number of loops as well as the start and end address locations.
In certain applications such as mobile telephones where the quest for reductions in energy consumption and size is ongoing and never satisfied, these additional overhead requirements for program loop execution have become undesirable.